title: Cytotoxic polyketide derivatives from the South China Sea sponge Plakortis simplex.
abstract: Five new polyketides, plakortoxides A (1) and B (2), simplextones C (3) and D (4), and plakorsin D (5), together with six known analogues (6-11) were isolated from the South China Sea sponge Plakortis simplex. Their structures were identified by spectroscopic and chemical methods, including NMR, MS, and IR. Experimental and calculated ECD spectra and the modified Mosher's method were used to determine the absolute configurations. Structurally, both plakortoxides A and B feature a butenolide coupled to an epoxide moiety, while simplextones C and D consist of γ-butyrolactone and cyclopentane moieties, and plakorsin D is a furan acetic acid polyketide. The cytotoxic activities of the isolates were tested, and compounds 8, 10, and 11 showed potent cytotoxicity against both K562 and HeLa tumor cell lines with IC50 values ranging from 0.8 to 5.3 μM. Compound 3 showed significant inhibitory activity against c-Met kinase.
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Zhang
authors.forename: Xuli
authors.initials: X
authors.lastname: Tang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Peifeng
authors.initials: P
authors.lastname: Li
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: de Voogd
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Ni
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Jin
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Yao
authors.forename: Pinglin
authors.initials: P
authors.lastname: Li
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D006367:HeLa Cells; D006801:Humans; D015394:Molecular Structure; D009792:Oceans and Seas; D047229:Plakortis / Q000737:chemistry; D061065:Polyketides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D061065:Polyketides; C582587:simplextone C